Usual thickening agents for foodstuffs, which have been known for a long time, are starch, starch derivatives, modified starch, pectins, alginic acid, alginates, guar flour, tragacanth, gum arabic, gelatin, carob-seed flour, galactomannan, xanthan, carrageen, karaya gum, tara gum, tamarind gum, gellan gum, mannan, maltodextrin etc. There is extensive literature on this subject, see for example Belitz, Grosch, Handbuch der Lebensmittelchemie [Manual of food chemistry], 4th edition, 1992, Springer Verlag, Berlin-Heidelberg-New York; R. L. Whistler, J. N. BeMiller, Carbohydrate Chemistry for Food Scientists, 1997, Eagan Press, St. Paul, USA; A. Nussinovitch, Hydrocolloid Applications, 1997, Blackie Academic & Professional, London.
Synergistic thickening agent compositions for printing inks and cosmetic formulations etc. are described in U.S. Pat. No. 4,540,510. U.S. Pat. No. 4,540,510 describes a composition comprising a polymer of an acrylamide-methylpropanesulfonic acid with a molecular weight above about a million and a water soluble polymer, which is selected from galactomannan gum, hydroxyalkyl ethers of galactomannan gum, hydroxyalkylcellulose ethers, polyalkylene oxide polymers and mixtures thereof, the polymers being present in the mixture in proportions such that a synergistic thickening effect is achieved in liquids.
Patent application US20060141127 describes a thickening system for beverages, especially for juices. The thickening system is made up of two components, a thickener and a thickening auxiliary, which display a synergistic effect. The synergistic effect makes it possible to reduce the amount of thickening agent used. The thickener is selected from flours, gums, modified food starches and mixtures thereof, and the auxiliary is selected from citrus flavoring, citrus oil, lemon peel and mixtures thereof.